CHEMOSPHERE
·
2016
·
IF 3.698
Xuexia Zhu,Yunfei Sun,Xingxing Zhang,Hailu Heng,Haihong Nan,Lu Zhang,Yuan Huang,Zhou Yang
The extensive application of herbicides has led to a serious threat of herbicide contamination to aquatic ecosystem . Herbicide exposure affects aquatic communities not only by exerting toxicity on single species but also by changing interspecific interactions . This study investigated the antigrazer defenses of the common green alga Scenedesmus obliquus against different herbicides [glyphosate, 2,4-dichlorophenoxyacetic acid (2,4-D), and atrazine] at various concentrations (0–2.0 mg L −1 ). In the presence of grazer ( Daphnia )-derived cues, S. obliquus populations without herbicides formed high proportions of multicelled (e.g., four- and eight-celled) colonies. This result confirms that S. obliquus exhibits a morphological defense against grazing risk. At the low concentration range of 0.002–0.02 mg L −1 , the three herbicides exerted no influence on the growth and photosynthetic efficiency of S. obliquus , and multicelled colonies showed constant proportions. At the high concentration range of 0.20–2.0 mg L −1 , atrazine significantly inhibited the algal growth and photosynthesis whereas glyphosate or 2,4-D did not. Nonetheless, these levels of glyphosate or 2,4-D remarkably decreased the proportion of multicelled colonies, with reduced numbers of cells per particle in Daphnia filtrate-treated population. No eight-celled colony was formed after treatment with atrazine at 0.20–2.0 mg L −1 despite the addition of Daphnia filtrate. These results suggest that herbicide exposure impairs antigrazer colonial morphs in phytoplankton although it is not sufficient to hamper algal growth. This phenomenon can increase the risk of predation by herbivores, thereby disrupting the inducible phytoplankton community. Furthermore, the predator-prey interactions between herbivores and phytoplankton can be potentially changed more seriously than previously considered.
研究领域:
生态学
·
水生生物学
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DOI
PubMed
高影响因子
ENVIRONMENTAL RESEARCH
·
2023
·
IF 8.3
Yue Wang,Weihao Ning,Shengnan Li,Changfei Gao,Rong Cui,Wanqian Guo,Jo-Shu Chang,Shih-Hsin Ho
The wide use of antibiotics in aquaculture has triggered global ecological security issue. Microalgal bioremediation is a promising strategy for antibiotics elimination due to carbon recovery, detoxification and various ecological advantages. However, a lack of understanding with respect to the corresponding regulation mechanism towards antibiotic stress may limit its practical applicability. The microalga Scenedesmus obliquus was shown to be capable of effectively eliminating ciprofloxacin (CIP), which is a common antibiotic used in aquaculture. However, the corresponding transcriptional alterations require further investigation and verification at the metabolomic level. Thus, this study uncovered the metabolomic profiles and detailed toxic and defense mechanisms towards CIP in S. obliquus using untargeted metabolomics. The enhanced oligosaccharide/polyol/lipid transport, up-regulation of carbohydrate and arachidonic acid metabolic pathways and increased energy production via EMP metabolism were observed as defense mechanisms of microalgal cells to xenobiotic CIP. The toxic metabolic responses included: (1) down-regulation of parts of mineral and organic transporters; (2) electrons competition between antibiotic and NAD during intracellular CIP degradation; and (3) suppressed expression of the hem gene in chlorophyll biosynthesis. This study describes the metabolic profile of microalgae during CIP elimination and reveals the key pathways from the perspective of metabolism, thereby providing information on the precise regulation of antibiotic bioremediation via microalgae.
研究领域:
环境科学
·
分子生物学
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产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Zhiheng Li,Jiazheng Chen,Jie Chen,Jiaojun Jin,Hanmei Chen,Huijun Liu
Due to the persistence of ionic liquids (ILs) in aquatic environments, it is necessary to reveal their ecological risk to aquatic organisms. Herein, the biotoxicity of two alkyl-methylimidazolium nitrate ILs ([C 10 mim]NO 3 and [C 12 mim]NO 3 ) against Scenedesmus obliquus were studied. Results showed that the growth inhibition of S. obliquus increased with increasing concentrations of ILs, maximum values of 94.61% at 4 mg/L of [C 10 mim]NO 3 and 97.34% at 0.8 mg/L of [C 12 min]NO 3 were observed. The fluorescence parameters of photosystem II, such as light quantum yield and electron transfer rate, showed a negative relationship with the exposure dose. [C 12 mim]NO 3 had a more significant effect than [C 10 mim]NO 3 . Moreover, the redox homeostasis of algae was disrupted; the accumulation of reactive oxygen species , leading to obvious inhibition of superoxide dismutase and catalase activities was observed. A metabolomic analysis indicated that the contents of most metabolites were reduced significantly, and fructose and galactose decreased significantly by 42.3% and 88.6%, respectively, in the [C 10 mim]NO 3 treatment compared to those in the control. The inhibition of amino acid biosynthesis and glyoxylate and dicarboxylate metabolism explained the more serious biotoxicity of [C 12 mim]NO 3 than that of [C 10 mim]NO 3 . This study facilitates a better understanding of the environmental safety and ecological risks of ILs.
研究领域:
环境科学
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植物生理学
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产品关联
DOI
PubMed
高影响因子
SCIENCE OF THE TOTAL ENVIRONMENT
·
2022
·
IF 10.753
Xuanhe Jia,Yueqiang Pan,Xuexia Zhu
Driven by anthropogenic activities, freshwater salinization has become an emerging global environmental issue . Recent studies indicate that salinization increases the mobility of heavy metals in soil and causes higher flux into surface waterbodies. The present study assessed the combined effects of salinization (0, 3, 6 PSU) and the heavy metal Cd 2+ (0, 0.2, 0.4 mg L −1 ) on the anti-grazing colony formation and population growth of Scenedesmus obliquus , a common freshwater alga. The results showed that the increase in salinity promoted colony formation of S. obliquus with or without the presence of grazing cues and, in contrast, Cd 2+ contamination depressed the defensive colony formation of S. obliquus to Daphnia filtrate. The increase in both salinity and Cd 2+ concentration depressed the population growth of S. obliquus , including impaired photosynthesis and a decreased population growth rate. Salinization moderated the negative effects of Cd 2+ on defensive colony formation of S. obliquus , suggesting increased absorption of Cd 2+ ions by a thicker outer layer of the algal cell wall under saltier conditions. As a result, larger defensive colonies of S. obliquus under freshwater salinization may cause higher bioaccumulation of heavy metals by algal cells and heavier influence on zooplankton. This study provides evidence that freshwater salinization could interfere with plankton interactions by affecting algal defense and growth, which may lead to bottom-up cascading effects on freshwater food webs.
研究领域:
生态学
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环境科学
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产品关联
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
·
2024
·
IF 7.4
Yuxin Zhou,Di Zhu,Yan Peng,Yiming Zhu,Yongni Shao
This study introduces a novel approach for the rapid detection of exchangeable heavy metal pollution in soil, utilizing Scenedesmus obliquus as a bioadsorbent. Terahertz spectroscopy was used to analyze the cell wall proteins and functional groups of S. obliquus following physical adsorption. This analysis enabled the deduction of the types and concentrations of exchangeable heavy metal ions in soil. We established a prediction model for heavy metal concentrations using partial least squares (PLS) regression, achieving optimal detection times: 10 min for Pb 2+ , 20 min for Ni 2+ , and 30 min for Co 2+ . Validation with real surface soil samples demonstrated excellent accuracy rates: 97.8 % for Pb 2+ , 91.8 % for Ni 2+ , and 90 % for Co 2+ . Notably, our method reduces the detection time to 0.5 hours, requires only 5 ml of sample volume, and enhances detection accuracy to 0.1 μg/L.
研究领域:
环境科学
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生物学
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产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2023
·
IF 13.6
Jie-Ru Jiang,Zhi-Feng Chen,Xiao-Liang Liao,Qian-Yi Liu,Jia-Ming Zhou,Shi-Ping Ou,Zongwei Cai
Tire wear particles (TWPs) are increasingly being found in the aquatic environment. However, there is limited information available on the environmental consequences of TWP constituents that may be release into water. In this study, TWP leachate samples were obtained by immersing TWPs in ultrapure water. Using high-resolution mass spectrometry and toxicity identification, we identified potentially toxic organic substances in the TWP leachates. Additionally, we investigated their toxicity and underlying mechanisms. Through our established workflow, we structurally identified 13 substances using reference standards. The median effective concentration (EC 50 ) of TWP leachates on Scenedesmus obliquus growth was comparable to that of simulated TWP leachates prepared with consistent concentrations of the 13 identified substances, indicating their dominance in the toxicity of TWP leachates. Among these substances, cyclic amines (EC 50 : 1.04–3.65 mg/L) were found to be toxic to S. obliquus . We observed significant differential metabolites in TWP leachate-exposed S. obliquus , primarily associated with linoleic acid metabolism and purine metabolism. Oxidative stress was identified as a crucial factor in algal growth inhibition. Our findings shed light on the risk posed by TWP leachable substances to aquatic organisms.
研究领域:
环境科学
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毒理学
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产品关联
DOI
PubMed
高影响因子
Scientific Reports
·
2017
·Vol. 7
·期 1
·1-12
·
IF 4.259
He Meilin,Yan Yongquan,Pei Feng,Wu Mingzhu,Gebreluel Temesgen,Zou Shanmei,Wang Changhai
Carbon nanotubes (CNTs), α-Fe 2 O 3 nanoparticles (nano Fe 2 O 3 ) and MgO nanoparticles (nano MgO) were evaluated for the effects on algae growth and lipid production. Nano Fe 2 O 3 promoted cell growth in the range of 0–20 mg·L −1 . CNTs, nano Fe 2 O 3 and nano MgO inhibited cell growth of Scenedesmus obliquus at 10, 40 and 0.8 mg·L −1 respectively. Neutral lipid and total lipid content increased with the increasing concentration of all tested nanoparticles. The maximum lipid productivity of cultures exposed to CNTs, nano Fe 2 O 3 and nano MgO was observed at 5 mg·L −1 , 5 mg·L −1 and 40 mg·L −1 , with the improvement by 8.9%, 39.6% and 18.5%. High dose exposure to nanoparticles limited increase in lipid productivity, possibly due to the repression on cell growth caused by nanoparticles-catalyzed reactive oxygen species (ROS) generation, finally leading to reduction in biomass and lipid production. Reduced accumulation of fatty acids of C18:3n3, C18:3n6 and C20:2 was observed in cells exposed to nanoparticles.
研究领域:
微生物学
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生物技术
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产品关联
DOI
PubMed
高影响因子
MOLECULES
·
2023
·Vol. 28
·期 12
·4774
·
IF 4.6
Qingqing Xiang,Ying Zhou,Chengxia Tan
Prothioconazole (PTC) is a broad-spectrum triazole fungicide with one asymmetric center and consists of two enantiomers,R-(−)-PTC andS-(+)-PTC. To address the concern of its environmental safety, the enantioselective toxic effects of PTC onScendesmus obliquus(S. obliquus) were investigated. PTC racemates (Rac-PTC) and enantiomers exhibited dose-dependent acute toxicity effects againstS. obliquusat a concentration from 1 to 10 mg·L−1. The 72 h-EC50 value ofRac-,R-(−)-, andS-(+)-PTC is 8.15, 16.53, and 7.85 mg·L−1, respectively. The growth ratios and photosynthetic pigment contents of theR-(−)-PTC treatment groups were higher than theRac- andS-(+)-PTC treatment groups. Both catalase (CAT) activities and esterase activities were inhibited in theRac- andS-(+)-PTC treatment groups at high concentrations of 5 and 10 mg·L−1, and the levels of malondialdehyde (MDA) were elevated, which exceeded the levels in algal cells for theR-(−)-PTC treatment groups. PTC could disrupt the cell morphology ofS. obliquusand induce cell membrane damage, following the order ofS-(+)-PTC ≈Rac-PTC >R-(−)-PTC. The enantioselective toxic effects of PTC onS. obliquusprovide essential information for its ecological risk assessment.Keywords:prothioconazole;toxicity effects;Scenedesmus obliquus;enantioselectivity
研究领域:
环境科学
·
毒理学
·
生态学
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产品关联
DOI
PubMed
高影响因子
CHIRALITY
·
2016
·Vol. 29
·期 2
·61-69
·
IF 2.025
Peng Xu,Ledan Huang
In this study the stereoselective bioaccumulation and transformation of triadimefon and the toxicity of triadimefon and its metabolite triadimenol to the green algae Scenedesmus obliquus were studied. In growth inhibition experiments, triadimenol was more toxic than triadimefon, and (1S,2R)-triadimenol, which has the largest fungicidal activity, presented the highest toxicity to the algae. In bioaccumulation experiments, triadimefon was rapidly taken up by algae cells, and the decrease in the concentration of triadimefon was accompanied by an increase in triadimenol. The transformation of S-(+)- triadimefon was faster than that of the R-(−)-enantiomer, resulting in four triadimenol stereoisomers at different forming rates: B2 (1S, 2S) > B1 (1R, 2R) > A2 (1S, 2R) > A1 (1R, 2S). Thus, it is necessary to explore the enantioselective toxicology and ecological fate of these chiral pesticides in an environmental risk assessment. Also, their metabolites should be paid specific attention to since they may pose higher ecological risks.
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DOI
高影响因子
AQUATIC TOXICOLOGY
·
2025
·
IF 4.3
Wei Hong,Fan Zhang,Zhuang Wang
Graphdiyne (GDY), an emerging 2D carbon nanomaterial, holds promise yet remains unexplored for environmental hazards. Herein, we investigated the toxicity effects and mechanisms of GDY towards the freshwater microalga Scenedesmus obliquus at environmentally relevant concentrations. The results revealed that 1 mg/L of GDY inhibited the growth of the algae and significantly induced a decrease in photosynthetic pigments. Exposure to 0.1 and 1 mg/L of GDY led to a reduction in cell membrane permeability and induced intracellular oxidative stress in the algae. Further, 1 mg/L of GDY caused oxidative damage to the algal cells. Molecular modeling indicated that GDY could directly affect the stability of dsDNA fragment. Transcriptome analysis showed that GDY at 1 mg/L influenced the expression of 2216 genes, with the glycerolipid metabolism pathway being enriched significantly. Metabolome analysis identified 129 differentially expressed metabolites (DEMs) in the algae exposed to 1 mg/L of GDY, revealing three significantly disrupted pathways: glycerophospholipid metabolism, pentose phosphate pathway, and flavonoid biosynthesis. The integrated transcriptome and metabolome analysis suggested that GDY exposure downregulated the level of a lysophosphatidylcholine species (LPC 18:3) by inhibiting the expression of genes related to FMN binding molecular functions. Simultaneously, the algae responded to GDY exposure by upregulating genes involved in the biological process of carbohydrate metabolic process and the molecular function of hydrolase activity, as well as increasing the levels of DEMs, specifically a lysophosphatidic acid species (LPA 16:4). This study elucidates the stress mechanisms induced by GDY in aquatic organisms and emphasizes the importance of monitoring its acute biological effects.
研究领域:
环境科学
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分子生物学
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产品关联
DOI
PubMed
高影响因子
AQUATIC TOXICOLOGY
·
2025
·
IF 4.3
Tianlie Luo,Jingjing Shi,Ping Zhang,Shuang Yang,Guo Liu,Willie J.G.M. Peijnenburg
In this study, Scenedesmus obliquus ( S. obliquus ) has been employed as a model organism to investigate the bioaccumulation, metabolism, and toxicity mechanisms of tricresyl phosphate (TCP). The results indicated that S. obliquus enhanced TCP degradation in water by 97% after 14 days. The bioaccumulation factor of tricresyl phosphate in S. obliquus were calculated to be 8. When exposed to a high concentration of TCP (160 μmol/L), the algal growth rate was initially negative at 24 h, but gradually recovered over time. By 96 h, the inhibition rate was 64.74% and the EC 50 values was determined to be 86.41 μmol/L. Prolonged exposure to TCP substantially inhibited photosynthesis in S. obliquus , as indicated by a significant reduction in chlorophyll content. The addition of humic acid (HA), a representative substance of dissolved organic matter, exacerbated TCP toxicity by increasing ROS production, indicating a synergistic effect between HA and TCP. Conversely, a mixed nitrogen source reduced TCP toxicity. Four TCP metabolites were identified, resulting from hydroxylation, ketonization, hydrolysis, and ester bond cleavage. ECOSAR analysis revealed that these metabolites exhibit lower toxicity compared to TCP. These findings indicate that metabolic transformations within the algae may mitigate TCP toxicity, whereas HA significantly exacerbates TCP-induced oxidative stress. This study offers novel insights into the ecological risks of TCP in aquatic environments, especially in the presence of natural organic matter.
研究领域:
环境科学
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毒理学
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产品关联
DOI
PubMed
高影响因子
Plants-Basel
·
2020
·Vol. 9
·期 12
·1748
·
IF 2.762
Zhou Li,Philippe Juneau,Yingli Lian,Wei Zhang,Shanquan Wang,Cheng Wang,Longfei Shu,Qingyun Yan,Zhili He,Kui Xu
The effects of the photocatalytic toxicity of titanium dioxide nanoparticle (nano-TiO2) on phytoplankton are well understood. However, as UV light intensity decreases sharply with the depth of the water column, the effects of nano-TiO2itself on deeper water phytoplankton, such as green algae, need further research. In this research, we investigated the effects of three sizes of TiO2(10, 50 and 200 nm) on the photosynthetic and antioxidative processes ofScenedesmus obliquusin the absence of UV light. We found that 50 nm and 10 nm TiO2(10 mg/L) inhibited growth rates and the maximal photosystem II quantum yield compared to the control inScenedesmus obliquus. The minimal and maximal fluorescence yields, and the contents of reactive oxygen species and lipid peroxidation, increased, indicating that photosynthetic energy/electrons transferred to oxygen and induced oxidative stress in nano-TiO2-treated samples. In addition, we found that aggregations of algae and 10 nm TiO2were present, which could induce cell membrane disruption, and vacuoles were induced to cope with nano-TiO2stress inScenedesmus obliquus. These results enhance our understanding of the effects of nano-TiO2on the photosynthetic and antioxidative processes of green algae, and provide basic information for evaluating the ecotoxicity of nano-TiO2in freshwater ecosystems.Keywords:titanium dioxide nanoparticle;photosynthesis;oxidative stress;Scenedesmus obliquus
研究领域:
环境科学
·
水生生态学
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植物生理学
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DOI
PubMed
高影响因子
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